Lindane (r-Hexachlorocyclohexane; r-Benzene hexachloride) is a popular insecticide. It is of interest to investigate the possible damaging action of this insecticide which is found in significant concentrations in everyday food (WHO, 1973). Male and female B6C3F1 mice are given Lindane at doses of 0, 10, 20 or 40 mg/kg daily for 3 consecutive days by gavage. Animals are killed on days 1, 2, 5 and 28 after the final treatment to study the histopathology, hematology and myelotoxicity of Lindane. We also examine the recovery of mice and the residual marrow effects following stress of radiation.